Computational analysis of the dose rates at JSI TRIGA reactor irradiation facilities

K Ambrožič; G Žerovnik; L Snoj

doi:10.1016/j.apradiso.2017.09.022

Computational analysis of the dose rates at JSI TRIGA reactor irradiation facilities

Appl Radiat Isot. 2017 Dec:130:140-152. doi: 10.1016/j.apradiso.2017.09.022. Epub 2017 Sep 22.

Authors

K Ambrožič¹, G Žerovnik², L Snoj³

Affiliations

¹ F8 reactor physics division, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: klemen.ambrozic@ijs.si.
² F8 reactor physics division, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: gasper.zerovnik@ijs.si.
³ F8 reactor physics division, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: luka.snoj@ijs.si.

PMID: 28965017
DOI: 10.1016/j.apradiso.2017.09.022

Abstract

The JSI TRIGA Mark II, IJS research reactor is equipped with numerous irradiation positions, where samples can be irradiated by neutrons and γ-rays. Irradiation position selection is based on its properties, such as physical size and accessibility, as well as neutron and γ-ray spectra, flux and dose intensities. This paper presents an overview on the neutron and γ-ray fluxes, spectra and dose intensities calculations using Monte Carlo MCNP software and ENDF/B-VII.0 nuclear data libraries. The dose-rates are presented in terms of ambient dose equivalents, air kerma, and silicon dose equivalent. At full reactor power the neutron ambient dose equivalent ranges from 5.5×10³Svh^-1 to 6×10⁶Svh^-1, silicon dose equivalent from 6×10²Gy/h_si to 3×10⁵Gy/h_si, and neutron air kerma from 4.3×10³Gyh^-1 to 2×10⁵Gyh^-1. Ratio of fast (1MeV<E) vs. thermal neutrons (E<0.625eV) ranges from 1.5 to 8.4×10^-2,γ ray ambient dose equivalent at full reactor power from 3.4×10³Svh^-1 to 3.6×10⁵Svh^-1 and γ air kerma range 3.1×10³Gyh^-1 to 2.9×10⁵Gyh^-1.

Keywords: ANSI-ANS6.1.11977; Flux to dose conversion factors; ICRP-21; ICRP-74; Irradiation positions; Neutron flux and spectrum; Research reactor; TRIGA; γ flux and spectrum.